CPR - Advanced Life Support

Question 1

What are the next steps in the CPR algorithm after basic life support?

Answer 1

1. Monitoring
2. Obtaining vascular access
3. Administer reversals

Question 2

When do you start advanced life support?

Answer 2

After the first 2 minutes of basic life support

Question 3

What is involved in monitoring?

Answer 3

Electrocardiography gram - ECG
Capnography
Clinical changes

Question 4

What does capnography tell you?

Answer 4

End tidal CO2 (ETCO2)
Most useful tool for monitoring
Measure perfusion
○ Movement of carbon dioxide from the tissues to the lungs
○ i.e. measures movement of blood
>15-20mmHg = Good compressions

Question 5

What does ECG tell you?

Answer 5

Heart rate/rhythm
Does NOT tell you about perfusion/cardiac output
Can assess if it is shockable rhythm or not (use defibrillator?)
* Ventricular Fibrillation
* Pulseless Ventricular Tachycardia

Question 6

What clinical changes can you assess?

Answer 6

• Pulses – difficult to palpate
  
  • Mucous membrane colour
  • Eye position changes
    ○ central -> ventromedial
  • Pupil changes size
  • Palpebral, corneal, gag reflex may be noticed
  • Breathing or chest movements (twitches) resume
  • Lacrimation
  • Animal regains consciousness

Question 7

How can you establish vascular access?

Answer 7

Intravascular (IV)
Intraosseous (IO)
Intratracheal (IT)

Question 8

What are the options for IV route?

Answer 8

Cephalic
Saphenous
Jugular
Central so doesn’t need flushing
Dirty procedure - risk of infection

Question 9

Pros and Cons of using IV route

Answer 9

Ideal route of choice for drugs and fluids
Tricky during CPR because of movement
Jugular venous cannula is ideal for administration but risk of thrombophlebitis
Other veins not as effective but can ‘flush’ drug centrally

Question 10

Pros and cons of intraosseous route

Answer 10

As rapid as using peripheral veins
Would need to use drill in adult patients
Not common in first opinion practice
Useful in small animals and birds

Question 11

Methods of intraosseous route

Answer 11

Greater tubercle of humerus
Tibial crest or trochanteric fossa of femur

Question 12

Pros and cons of intratracheal route

Answer 12

Chest inflations will distribute drugs
Higher doses needed
Dilute and use urinary catheter inserted beyond carina

Question 13

Reversals/Antagonists examples

Answer 13

Atipamezole
Naloxone
Flumazenil

Question 14

Atipamezole use

Answer 14

Reverses Alpha-2 agonists (medetomidine)

Question 15

Naloxone use

Answer 15

Reverses opioids (methadone)

Question 16

Flumazenil use

Answer 16

Reverses Benzodiazepines (midazolam)

Question 17

When is it appropriate to administer a reversal agent?

Answer 17

After checking patient hospital drug records
Making sure you know why the patient is in
Make sure you know which drugs have been given

Question 18

When should you check the ECG?

Answer 18

AFTER the first compression cycle (2 mins)
Not possible to asses during compressions

Question 19

What does ventricular Fibrillation/Pulseless Ventricular Tachycardia mean?

Answer 19

Patient will be less responsive to basic life support (CPR)
Need to convert them
Defibrillator - need training, can be dangerous
Pre-cordial thump - need training
Medical conversion
Amiodarone/lidocaine
Carry on with basic life support after conversion

Question 20

What is asystole?

Answer 20

Flatline
No electrical or mechanical activity

Question 21

What is Pulseless Electrical Activity (PEA)

Answer 21

Can look normal on ECG
Electrical activity but no mechanical activity
More responsive to CPR than ventricular fibrillation
Can use drug therapy to augment

Question 22

Drug therapy examples

Answer 22

Adrenaline/epinephrine
Vasopressin/ADH
Atropine

Question 23

Adrenaline Use

Answer 23

Adrenergic agonist (a and b receptors)
Directs blood flow to heart by causing constriction of peripheral vessels and dilation of central ones
Positive inotrope - increases contraction of heart (increases CO)
Positive chronotrope - Increases heart rate

Question 24

Pros and cons of using adrenaline

Answer 24

‘shunts’ blood to heart from periphery
Increases myocardial oxygen demand
Low dose is recommended to reduce this

Question 25

Vasopressin/ADH use

Answer 25

Causes peripheral vasoconstriction - increasing blood pressure

Question 26

Pros and cons of vasopressin/ADH

Answer 26

Does not have deleterious effects on myocardial oxygen demand Similar efficacy to adrenaline - no better Expensive

Question 27

Atropine use

Answer 27

Inhibits the muscarinic actions of acetylcholine (parasympatholytic - preventing parasympathetic innervation) Removes suppression rather than stimulating

Question 28

Pros and cons of atropine

Answer 28

Parasympatholytic - different action to adrenaline Evidence doesn't show clear benefit Theoretically good for patients with high vagal tone Not recommended in rabbits (due to atropinase)

Question 29

Controversies examples

Answer 29

High dose adrenaline Fluid therapy Bicarbonate Open-chest CPR

Question 30

Controversies examples

Answer 30

High dose adrenaline Fluid therapy Bicarbonate Open-chest CPR

Question 31

Why is high dose adrenaline controversial?

Answer 31

Increased myocardial oxygen demand Increased rate of ROSC No increased survival rates Can be considered in prolonged arrest (>10 minutes)

Question 32

What is ROSC and how can you assess it?

Answer 32

Return of Spontaneous Circulation Use capnography - sudden increase in ETCO2 Use ECG - return of normal rhythm (careful could be PEA) Return of consciousness/movement/refexes

Question 33

Why is fluid therapy controversial?

Answer 33

Administration to euvolemic patients is associated with reduced coronary perfusion (can make them hypovolaemic) ONLY consider in patients with KNOWN hypovolaemia

Question 34

Why is bicarbonate controversial?

Answer 34

Basic - used to alkalise blood Metabolic acidosis is a common occurrence in CPA Mixed results in experimental studies Only consider when prolonged CPA

Question 35

Why is open-chat CPR controversial?

Answer 35

More effective than external compressions BUT requires significant resources during and in recovery Can be considered for intra-thoracic pathology

Question 36

Post-ROSC care

Answer 36

Many patients re-arrest so keep going until fully conscious Provide respiratory and cardiovascular optimisation Prevent hypothermia

Question 37

How do you provide respiratory optimisation?

Answer 37

○ Supportive oxygen +/- ventilation if required ○ Target PaO2 80-100mmHg or SpO2 94-98% ○ Beware hyperoxia and oxidative damage with reperfusion

Question 38

How do you provide cardiovascular optimisation?

Answer 38

If hypotensive Beware fluid overload, so use of vasopressor therapy is sensible

Question 39

How do you prevent hypothermia

Answer 39

Re-warm slowly Cover extremities Use heat pads